Devices for sensing accelerations are well known and have many uses.
One class of such devices, referred to herein as accelerometers, includes a proof mass mounted to a support by flexures via a support ring, and further includes capacitors. The proof mass is displaced from a datum position by an acceleration applied to the device along its sensing axis, and the resulting differential capacitance is sensed by a feedback circuit which in turn generates a current that can be applied to force balancing coils to return the proof mass to the datum position. The acceleration can thus be related to the magnitude of this current.
The support ring is clamped in position in the device, which can lead to thermal strains as well as mounting strains being coupled to the flexures, which in turn can lead to bias sensitivity to temperature and to mounting, respectively, which can cause bias error and thus degrade the sensitivity and performance of the device.
By way of general background, the following publications disclose various accelerator configurations: U.S. Pat. Nos. 3,702,073, 4,250,757, 4,498,342, 4,932,258, 5,111,694, 5,182,949, 5,287,744, and 5,763,779.